Processing payments for product purchases using mobile terminal devices, also known as mobile payments, is becoming increasingly common. In a mobile payment, electronic money, for example, is used; transaction information including payment information and product information is input to a mobile terminal device; and the information is sent on-line or off-line to a server for final processing. After processing, the transaction information is stored on the server. A problem with such mobile payments is issuing a receipt to the payer at the time of payment.
PTL 1 describes transaction information being sent from the server to the customer's mobile phone and displayed after a payment is made at an ECR (Electronic Cash Register) or POS (point of sales) terminal.